Ingredient review
Lithium Hydroxide
INCI: Lithium Hydroxide
Lithium hydroxide is a strong alkali used to adjust pH in some hair relaxers and soaps, but it can be irritating at high concentrations.
In plain English
Lithium hydroxide is a chemical that makes a product more alkaline (the opposite of acidic). In very small amounts, it helps adjust the pH of certain cosmetics, especially hair relaxers that need to be alkaline to work. Because it is a strong alkali, it can be irritating or even damaging to skin and hair if not carefully formulated and used as directed.
Review score
Safety, usefulness, and evidence
Higher-caution ingredient
The evidence base is useful, but some claims depend heavily on the formula.
Main practical flags: irritation is high; clogging risk is low.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- high
- Clogging risk
- low
Quick decision guide
Read the cautions before using
Lithium Hydroxide can be useful, but watch for high irritation potential.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Lithium Hydroxide.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
highMore likely to cause dryness, stinging, peeling, or reactivity if used too aggressively.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
Lithium hydroxide is an inorganic compound (a salt) that is a strong base. In cosmetics, it is used as a pH adjuster to raise the pH of a formula to a desired level, often in hair relaxers or soap products.
How it works
Lithium hydroxide dissociates in water to release hydroxide ions, which increase the pH of the product. In hair relaxers, this high pH helps break down the disulfide bonds in hair, allowing it to be reshaped. In soaps and cleansers, it helps saponify oils and maintain a stable pH.
Pros
Effective pH adjuster
Lithium hydroxide is a strong base that can precisely raise pH in small amounts, making it useful for products like hair relaxers that require a high pH to work.
Stable in formulations
It is chemically stable and does not degrade easily, helping maintain the intended pH over the product's shelf life.
Cons and cautions
High irritation risk
As a strong alkali, lithium hydroxide can cause skin burns, scalp irritation, and eye damage if used at too high a concentration or without proper precautions.
Potential for hair damage
In hair relaxers, the high pH can weaken hair fibers, leading to breakage, dryness, or chemical burns if left on too long or used too frequently.
Best for
- People using professional hair relaxers under guidance
- Formulators needing a strong pH adjuster
Use caution if
- People with sensitive, irritated, or damaged skin or scalp
- Those with eczema, psoriasis, or open wounds on the scalp
Usage tips
Safety summary
Lithium hydroxide is safe in cosmetics only at very low concentrations and with proper formulation. It is a strong irritant and should be used with caution, especially on sensitive skin or scalp. Regulatory bodies set strict limits to protect consumers.
Research notes
Research on lithium hydroxide in cosmetics is limited; most safety data come from industrial exposure studies. The Cosmetic Ingredient Review (CIR) panel has evaluated similar strong alkalis and recommends low concentrations and clear warnings.
Common label clues
- Typical concentration
- Very low (typically less than 1%)
- Regulatory status
- Approved for use in cosmetics in the EU and US as a pH adjuster, but subject to concentration limits and labeling requirements to ensure safe use.
- Common uses
- Hair relaxers, Soaps, Cleansers
- Environmental note
- Lithium hydroxide is synthetically produced; its environmental impact is minimal at cosmetic use levels, but lithium mining for other industries raises broader environmental concerns.
Good to know
- Lithium hydroxide is not commonly found in everyday skincare; it is more typical in specialty hair relaxers and some soaps.
- The concentration in cosmetics is tightly regulated to minimize irritation risk.
Common questions
What is Lithium Hydroxide in beauty products?
Lithium hydroxide is a chemical that makes a product more alkaline (the opposite of acidic). In very small amounts, it helps adjust the pH of certain cosmetics, especially hair relaxers that need to be alkaline to work. Because it is a strong alkali, it can be irritating or even damaging to skin and hair if not carefully formulated and used as directed.
What does Lithium Hydroxide do in a beauty product?
Lithium hydroxide dissociates in water to release hydroxide ions, which increase the pH of the product. In hair relaxers, this high pH helps break down the disulfide bonds in hair, allowing it to be reshaped. In soaps and cleansers, it helps saponify oils and maintain a stable pH.
Is Lithium Hydroxide safe for most people?
Lithium hydroxide is safe in cosmetics only at very low concentrations and with proper formulation. It is a strong irritant and should be used with caution, especially on sensitive skin or scalp. Regulatory bodies set strict limits to protect consumers.
Who should be careful with Lithium Hydroxide?
People with sensitive, irritated, or damaged skin or scalp Those with eczema, psoriasis, or open wounds on the scalp
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.